In all, there were 36*150 oranges initially. Out of the total, 72 went bad; the rest is 36*150-72 = 5328. She sold 5328 for c(300/2) each and got c(300/2)*5328 = c799200. Her profit was c16200 - hence, she bought originally for c799200 - c16200 = c78300. The cost of one basket was= c21750.